1. Field of the Invention
The present invention is generally related to a support system for an outboard motor and, more particularly, to a system that restricts the maximum movement, toward port or starboard, of a preselected portion of the outboard motor.
2. Description of the Related Art
Those skilled in the art of outboard motors are familiar with many different types of mounting systems for outboard motors. Typically, resilient mounts incorporate an elastomeric portion that isolates vibration from being transmitted to a marine vessel from the outboard motor. In addition, those skilled in the art are familiar with many different types of mounting bracket systems that attach an outboard motor to a transom of a marine vessel.
U.S. Pat. No. 3,599,594, which issued to Taipale on Aug. 17, 1971, discloses a sound and vibration isolating mount for an outboard motor. It includes a pair of mounts secured to the propulsion unit in a vertically spaced relation approximately in alignment with the neutral or roll axis of the propulsion unit and rearwardly of or behind the driveshaft. Each mount includes a crossbar which is supported by a resilient bushing within a casing and which has ends extending outwardly from the casing transversely to the direction of motion of the propulsion unit.
U.S. Pat. No. 4,482,330, which issued to Cook on Nov. 13, 1984, describes an outboard motor mounting apparatus. It comprises two slidably connected brackets, one for securing to the transom of the boat and one for carrying the outboard motor. It also has a hydraulic actuating cylinder connected between the two brackets for moving the motor mounting bracket along a vertical line relative to the bracket secured to the transom.
U.S. Pat. No. 4,826,460, which issued to Zuckerman on May 2, 1989, describes an outboard marine engine stabilizing device. It includes a plate having two spaced apart arms which are adapted to be connected to opposite sides of the powerhead of the motor and adapted to be connected to the steering arm of the motor at the end of the plate generally opposite to the location of the connection of the arms to the motor.
U.S. Pat. No. 4,964,354, which issued to Latham on Oct. 23, 1990, describes a steering plate for an outboard motor. It attaches to an outboard motor without disturbing the joint between engine mounting and driveshaft housing. The attachment fastens to the motor at the sides and rear in two parallel horizontal planes and a vertical plane for rigidity to resist forces in diverse directions.
U.S. Pat. No. 5,186,666, which issued to Stanley on Feb. 16, 1993, describes a marine motor drive unit mounting apparatus. It comprises first and second boat mounting members securable to a boat and lying in a boat plane and includes first and second motor mounting members securable to a motor and lying in a motor plane spaced apart from the boat plane by a distance. The motor plane has an angular orientation relative to the boat plane. The device for setting the motor mounting members in a position displaced from the boat mounting members is connected between the boat mounting members and the motor mounting members.
U.S. Pat. No. 5,647,781, which issued to Johnson on Jul. 15, 1997, describes an outboard motor support. It is intended to prevent damage from inadvertent pivoting of the motor during trailering. The support is attached to the motor and boat without making modifications thereto and handles are affixed to the spring loaded locking pins for easy manipulation.
U.S. Pat. No. 6,354,893, which issued to Sato on Mar. 12, 2002, describes a mounting structure for an outboard motor. In an outboard motor equipped with an engine mounted on an engine holder that is attached to a hull by a mounting device, and equipped with a crankshaft disposed more or less vertically within the engine and from which rotational force is transmitted to a propelling device by a driveshaft, the axis of the driveshaft is disposed in a position offset away from the axis of the crankshaft a little to the rear of the outboard motor, a pair of left and right mount holders are formed adjacent to the center of gravity of the outboard motor within the engine holder, the mount units are inserted into these mount holders from the front side of the engine holder, the driveshaft is inserted between the mount holders, and the mount holders are formed as close as possible to a protective wall for the driveshaft so that the mount holders can clear the protective wall.
U.S. Pat. No. 6,419,534, which issued to Helsel et al. on Jul. 16, 2002, discloses a structural support system for an outboard motor. The system is provided for an outboard motor which uses four connectors attached to a support structure and to an engine system for isolating vibration from being transmitted to the marine vessel to which the outboard is attached. Each connector comprises an elastomeric portion for the purpose of isolating the vibration. Furthermore, the four connectors are disposed in a common plane which is generally perpendicular to a central axis of a driveshaft of the outboard motor. Although precise perpendicularity with the driveshaft axis is not required, it has been determined that if the plane extending through the connectors is within 45 degrees of perpendicularity with the driveshaft axis, improved vibration isolation can be achieved. A support structure, or support saddle, completely surrounds the engine system in the plane of the connectors. All of the support of the outboard motor is provided by the connectors within the plane, with no additional support provided at a lower position on the outboard motor driveshaft housing.
U.S. Pat. No. 6,659,817, which issued to Anderson et al. on Dec. 9, 2003, discloses an alignment system for an outboard motor. First and second pliable members are each attached to an outboard motor and to a fixed location on the transom or transom bracket associated with the outboard motor. One pliable member is used on the starboard side of the outboard motor while another is used on the port side. As the outboard motor is tilted about its trim axis, the two pliable members work in coordination with each other to exert a force on the outboard motor in a direction away from any direction in which the outboard motor is rotated about its steering axis as it is being tilted about its trim axis.
U.S. Pat. No. 6,669,517, which issued to Alby et al. on Dec. 30, 2003, discloses a multiple part cowl structure for an outboard motor. The structure comprises first and second cowl members that are independent components. A first cowl member is attachable, by a latch mechanism, to a support structure of the outboard motor. The second cowl member is attachable by a latch mechanism, to both the first cowl member and the support structure.
U.S. Pat. No. 6,830,492, which issued to Magee et al. on Dec. 14, 2004, discloses a marine drive trim cylinder with a two stage damping system. The mounting bushings comprise inner and outer tubes with an elastomeric material disposed between the inner and outer tubes. The elastomeric material is structured to provide a soft rate of stiffness in response to relatively light loads, such as shifting loads, and a harder rate of stiffness in response to higher loads, such as during high thrust loads or wide open throttle operation of a marine vessel.
U.S. Pat. No. 7,198,530, which issued to Rothe et al. on Apr. 3, 2007, discloses a resilient mount system for an outboard motor. The support structure for an outboard motor provides a connection bar between an engine support structure and a steering structure. A tubular outer member is spaced apart from the attachment bar and connected to the attachment bar with an elastomeric member. Vibration isolation and consistency of deformation is achieved through the interaction of the individual elements of the structure.
U.S. Pat. No. 7,244,152, which issued to Uppgard on Jul. 17, 2007, discloses a support system for an outboard motor. An adapter system is provided as a transition structure which allows a relatively conventional outboard motor to be mounted to a pedestal which provides a generally stationary vertical steering axis. An intermediate member is connectable to a transom mount structure having a connector adapted for mounts with central axes generally perpendicular to a plane of symmetry of the marine vessel. Many types of outboard motors have mounts that are generally perpendicular to this configuration. The intermediate member provides a suitable transition structure which accommodates both of these configurations and allows the conventionally mounted outboard motor to be supported, steered, and tilted by a transom mount structure having a stationary vertical steering axis and pedestal-type configuration.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
Certain types of outboard motors place all of the resilient mounts above a preselected vertical position. Outboard motors of this type are described in U.S. Pat. Nos. 6,419,534 and 6,669,517. Because of this structure, the lower portion of the outboard motor is not directly connected to any stationary portion of the mount system. When the lower portion of the outboard motor is subjected to significant loads in either the port or starboard directions, the outboard motor can assume a position that varies significantly from a generally vertical axis. If this occurs, undesirable steering reactive forces can be felt by the operator of the marine vessel and control of the marine vessel can be adversely affected. Since outboard motors of this type exhibit many highly desirable characteristics such as reduced vibration and quiet operation, it would not be desirable to increase the stiffness of the support system or provide additional attachment between the lower portion of the outboard motor and the support brackets which are attached to the marine vessel. It would therefore be significantly beneficial if an outboard motor could be provided with a relatively soft support system when it is operated at low speeds, but with a strong resistance to deflection of the outboard motor from a generally vertical axis when it is operated at higher speeds and loads. It would also be beneficial if the outboard motor of this general type could continue to be supported only at a location above the vertical center of the outboard motor while also being provided with a way to physically restrict the port and starboard movement of the lower portion of the outboard motor when it is operated at higher speeds and loads.